e-line

The e-line is the system of automation instruments that FEA made under the licence bought in 1965 from Hokushin, a member of the Yokogawa group of Japan: field and panel instruments for automatic process control – pressure, level, flow, temperature and pH transducers, adaptors and amplifiers for them, controllers, analogue computing units, indicators and paper chart recorders [1]. It used the unified 2–10 mA signal and 1960s technology with germanium transistors; in the 1970s the transistor circuits were replaced with integrated or hybrid circuits using the unified 4–20 mA signal, as in the Foxboro licence instruments [1]. The automation institute IPA moved the Hokushin equipment to silicon technology in 1966–1970 [1].